<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../assets/js/vue.js"></script>
</head>
<body>
    <div id="app">
        选项是：
        <input type="radio" name="gre" id="" value="a">
        <input type="radio" name="gre" id="" value="b" checked>
        <input type="radio" name="gre" id="" value="c">
        <input type="radio" name="gre" id="" value="d">
        <div>
            <input type="radio" name="gree" id="" value="e"
            :checked="v1=='e'" >
            <input type="radio" name="gree" id="" value="f"
            :checked="v1=='f'">
        </div>
    </div> 
    <script>
        new Vue({
            el:"#app",
            data:{
                v1:'e'
            }
        })
    </script>   
</body>
</html>